I have the first Green results from using my ISY.
Here is what I did: I use the ISY to control what I call "Away Mode" for my home. The goal is to keep energy usage to a minimum while nobody is at home. I have a 3,800 sqf house and I live here with my youngest daugher (highschool senior). I use the ISY to program the thermostat to cool the house down while I am at work and my daughter is in school, I also have a KPL button to manually set the house to "Away Mode". A motion detector in the garage senses one of us coming home and switches off the Away mode and heats up the house. I also control my modes over the internet connection to my ISY. In addition I have a "Bedtime" mode that colls the house down a little when I retire to my bedroom and watch TV there.
Now, the first numbers are in!
Compared to last year (same month, same avg. outside temp), I reduced my average THRM use per day from 4.1 to 3.3, which is more than 20%! Costwise the difference is approx. $35 for that month. I attribute that to the flexibility of programming the ISY over a simple 7 day programmable thermostat.